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CONFERENCE ON HEAT & DETACHMENT iru CRUSTAL EXTENSION ON CONTINENTS AN^ PLANETS * SEDONA, ARIZONA OCTOBER 10 12,1.985 {BBSB-CR- 176837]1 2APEBS PBXSEPTED TO TfiE 186-3 13 19 CGNFEAEMCE 8N HEAT ANG DETACEBEIT IW EBUSTBL THB U EXZEMSIOH QB CQNTIMENlS AND Z-IAMETS [Lunar B86-3 3 265 and Planetary Inst,) 359 p CSCZ 086 fnclas G3/46 42963 Sponsored by Lunar and Planetary Institute U.S. Geological Survey, Flagstaff American Geophysical Union Geological Society of America Rio Grande Rift Consortium UNIVERSITIES SPACE RESEARCH ASSOCIATION LUNARAND PLANETARYINSTITUTE 3303 NASA ROAD 1 HOUSTON, TEXAS 77058 Papers Presented to the Conference on HEAT AND DETACHMENT IN CRUSTAL EXTENSION ON CONTINENTS AND PLANETS Sedona, Arizona October 10-12, 1985 \ Sponsored by: Lunar and Planetary Institute U.S. Geological Survey, Flagstaff American Geophysical Union Geological Society of America Rio Grande Rift Consortium Compiled by: Publications Office Lunar and Planetary Institute 3303 NASA Road One Houston, TX 77058-4399 LPI CONTRIBUTION NO. 575 Compiled ifi 1985 by the Lunar and Planetary Institute Material in tHis volume may be copied Without restraint for libkary, abstract service, edkational, or research purposes; hdwetrer; republication of any papek or portion thereof requires written permiss?on from the author as well as appropriate acknowledpmeht of this publication. PREFACE This volume contains abstracts that have been accepted by the Program Committee for presentation at the Conference on Heat and Detachment in Crustal Extension on Continents and Planets, held in Sedona, Arizona, October 10-12, 1985. Program Committee members included the following: Conveners: I. Lucchitta (U.S. Geological Survey, Flagstaff) P . Morgan (Purdue ~niversi t y)' L. ~oderblom (U.S. ~eologic~lSurvey, Flagstaff) Committee Members: E. Frost (San Diego State University) G. R. Keller (University of Texas, El Paso) A. S. McEwen (~riZ0nastate University, Tempe) J. Sass (U.S. Geological Survey, Flagstaff) Logistics and administrative support for the conference was provided by the LPI Projects Office. The Lunar and Planetary Institute is operated by the Universities Space Research Association under contract no. NASW-3389 with the National Aeronautics and Space Administration. iii CONTENTS Extent and Character of Early Tertiary Penetrative Deformation, Sonora, Northwest Mexico T. H. Anderson Rifting on Venus: Implications for Li thospheric Structure W. B. Banerdt and M. P. Golombek Thermal Regimes in the Detachment Fault Environment as Deduced from Fluid Inclusions R. E. Beane, J. Wilkins, Jr., and T. L. Heidrick Heat Flow and continental Breakup: The Gulf of Elat (Aqaba) Z. Ben-Avraham and R. P. Von Herzen Evolution of Basin and Range Structure in the Ruby Mountains and Vicinit y , Nevada D. D. Blackwell, N. M. Reese, and S. A. Kelley' Late Cretaceous Extensional Tectonics and Associated Igneous Activity on the Northern Margin of the Gulf of Mexico Basin R. L. Bowen and D. A. Sundeen A Regional 17-1 8 Ma Thermal Event in Southwestern Arizona W. E. Brooks Geometric and Chronologic Evolution of the Verde and Payson Basins of Central Arizona and Possible Relationships to Detachment Faulting D. S. Brumbaugh Potassium etas so mat ism of volcanic and Sedimentary Rocks in Rift Basins, Calderas, and Detachment Terranes C. E. Chapin and J. I. Lindley Extensional Tectonics and Collapse Structures in the Suez Rift (Egypt) P. Y. Chenet, B. Colletta, G. Desforges, E. Ousset, and E. A. Zaghloul Tectonic Determinations of Lithospheric Thicknesses on Ganymede and Callisto S. K. Croft 34 Metamorphic Core Complexes -- Expression of Crustal Extension by Ductile-Bri ttle Shearing of the Geologic Column G. H. Davis 38 Thermal History of a Metamorphic Core Complex R. K. Dokka, M. J. Mahaffie, and A. W. Snoke PgECEDtHQ PAGE BLANjt MOT FOWm Thermal-Mechanical Response to Simple Shear Extension K. P. Furlong Lithospheric Strength of Ganymede: Clues to Early Thermal Profiles from Extensional Tectonic Features M. P. Golombek and W. B. Banerdt Io: Mountains and Crustal Fxtension M. J. Heath Pn Velocity Beneath Western New Mexico and F~gternArizona L. H. Jaksha Brittle Extension of the Continental Crust AJong a Rqpted SyqDpq of Low-Angle Normal Favlts: Colorado River Extengiofial Corridor B. E. John and K. A. Howard 58 Thermomechanical Modeling of the Colorado Plageau-Basin and Range Transition Zone M. D. Londe 59 Heat and Detachment in Core-Complex Excension I. "Lucchitta Heat Flow Increase Following the ~igeof Mantle Ig~i;herqsand Crustal Thinning J.-C. Mareschal and G. Bergantz 69 Relations Between Extensional Tectonics and Magmatism Within the Southern Oklahoma Aulacogen D. A. McConnell and M. C. Gilbert 7 1 Hot-spot Tectonics on Io A. S. McEwen The Heart Mountain Fault: Implications for the Dynaqics of Decollement H. J. Melosh 81 Oceanic Structures of the Earth and the Qosth Depression of Mars: A Comparison of the Formation 4echanism-s E. E. Milanovsky and A. M. Nikishin The Evolution of Rifting Process in the Tectonic Eiistary of the Earth E. E. Milanovsky and A. MI. Nikishin Extensional Tectonics af the Sa turnian Satelli tes J. M. Moore Lithospheric and Crustal Thinning I. Moretti Thermal Control of the Style of Extensional Tectonics P. Morgan Extensional Tectonics on Continents and the Transport of Heat and Matter H. J . Neugebauer On the Differences in Continental Rifting at the Earth, Mars, and Venus A. M. Nikishin and E. E. Milanovsky 101 Heat and Extension at Mid- and Lower Crustal Levels of the Rio Grande Rift K. H. Olsen, W. S. Baldridge, and J. F. Callender 104 Low-angle Normal Faulting and Isostatic Response in the Gulf of Suez: Evidence from Seismic Interpretation and Geometric Reconstruction S. K. Perry and S. Schamel 106 The Relationship of Extensional and Compressional Tectonics to a Precambrian Fracture System in the Eastern Overthrust Belt, USA H. A. Pohn 11 1 Low-angle Normal Faults -- Low Differential Stress at Mid Crustal Levels? W. L. Power 11 3 Late Precambrian Aulacogens of the North China Craton X. Qian Radial Rift and Block Tectonics Around the Tharsis Bulge: Introductional Postulation J. Raitala 118 Heat Flow and Thermal Processes in the Jornada Del Muerto, New Mexico M. Reiter 123 Cenozoic Extension and Magmatism in Arizona S. J. Reynolds and J. E. Spencer A Numerical Study of Forced Lithospheric Thinning G. Schubert, C. A. Anderson, and E. Fishbein Kinematics of a Large-scale Intraplate Extending Lithosphere: The Basin-Range R. B. Smith and P. K. Eddington 135 Rift Systems on Venus: An Assessment of Mechanical and Thermal Models S. C. Solomon and J. W. Head 138 Possible Role of Crustal Flekure in the Initial Detachment of Ejrtensional Allochthons J. E. Spencer The Effects of Strain Heating in ~itho~phericStretching Models M. Stafitonj D. Hodg'eT, and F. Cozzakelli 145 Geometry of Miocene Extensional Defofrmation, Lower Coforac?~ River Region, Southeastern California an& soukhtj&~terhkrizofia: Evidence for the Presence of a Regional Low-Angle Nbrmal Fault R. M. Tosdal and D. R. sherrd 147 Similarities and Contrasts in Tectonic a'hd Volcanic Style and History Along the Colorado Plateaus-to-Ba3ih and Range Transition Zdne in Westerfi Arizona : ~eoidgicFramebork foh Tertiary Extension&l $tectonics R. A. Yobhg, E. H. McKee, J. H. Hartman, afid A; k. Si&6hs Ductile Extension of Planetary Lithos2jheres ' M. T. Zuber and E. M. PBrhentier Author Index viii EXTENT AND CHARACTER OF EARLY TERTIARY PENETRATIVE DEFORMATION, SONORA, NORTHWEST MEXICO; T. H. Anderson, Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, PA 15260 Reconnaissance field work has led to the recognition of extensive Early Tertiary gneiss and schist which are distinguished by weakly developed to highly conspicuous northeast to east-trending stretching lineation commonly accompanied by low-dipping foliation. This structural fabric has been imposed on Precambrian to Paleogene rocks. Regionally, minimum ages of deformation are based upon interpreted U-Pb isotopic ages from suites of cogenetic zircon from the Paleogene orthogneiss. Locally, the interpreted ages indicate that ductile deformation continued as late as Oligocene (Anderson and others, 1980; Silver and Anderson, 1984). The consistency of the deformational style is such that, although considerable variation in intensity exists, the fabric can be recognized and correlated in rocks away from the Paleogene orthogneiss. Outcrops of Tertiary gneiss and schist (Tgn-s) generally coincide with a north-northwesterly-trending belt, recognized by L.T. Silver (Silver and Anderson, 1984), within which the rock and mineral isotopic systems record a pronounced mid-Tertiary thermal disturbance. The axis of the belt, which broadens northward, extends from Mazatan, east of Hermosillo, toward Nogales on the Sonora-Arizona border. Deformed rocks do not crop out continuously within this band but occur as domains segmented by sharp or transitional boundaries. In northern Sonora extensive outcrops of Tgn-s exist between the Mojave-Sonora megashear and a series of straight, northwesterly-trending lineaments which are interpreted as normal faults, orthogonal to the 'stretching dyrection, developed ih brittle sequences. Within this extensive area Tgn-s have been formed from supracrustal rocks of Jurassic(?) age intruded by the "Laramide" and younger plutons. Outside this region the volcanic and volcaniclastic rocks of the Jurassic(?) sequence are characterized by tight folds which commonly trend northwesterly to westerly. These folds are